MMSE信道估计下的软输出MMSE MIMO检测算法  

Soft-output MMSE MIMO Detector under MMSE MIMO Channel Estimation

作　　者：王军[1] 李少谦[1] 

机构地区：[1]电子科技大学通信抗干扰技术国家级重点实验室,成都610054

出　　处：《信号处理》2009年第9期1371-1375,共5页Journal of Signal Processing

基　　金：自然科学基金资助项目(No.60702073);国家基础科研项目(No.A14200810150);"863"项目(No.2007AA01Z209);"973"项目(No.2009CB320405)

摘　　要：信道编码的MIMO无线通信系统中,MIMO信号检测器需要输出编码比特的对数似然比,以获得更好的误码率性能。现有的软输出MMSE MIMO检测算法基于理想信道估计得到,在实际信道估计下会导致性能损失。本文针对MMSE MIMO信道估计,基于MMSE信道估计的统计特性,推导了考虑信道估计误差影响的新的软输出MMSE MIMO检测算法。仿真结果表明,相对于现有的软输出MMSE MIMO检测算法,所提出的算法可以显著降低由于信道估计误差导致的残留误码平层,而增加的计算复杂度可以忽略不计;同时,所提算法对信道估计误差方差的相对误差不敏感,具有实际应用的价值。In channel coded multiple-input multiple-output （MIMO） wireless communication systems, MIMO signal detector should output log-likelihood ratio （LLR） of each coded bit so that better bit-error-rate performance can be obtained. Existing soft-output minimum mean square error （MMSE） MIMO detector is derived based on perfect channel estimation. In practical channel estimation,it inevitably suffers from performance degradation. In this paper, a novel MMSE MIMO detector is proposed with respect to MMSE MIMO channel estimation. This proposed detector takes channel estimation errors into account by the statistical characteristics of MMSE MIMO channel estimation. When compared with existing soft-output MMSE MIMO detector, simulation results show that the proposed novel detector can remarkably reduce the residual error floor due to the channel estimation errors ,while achieving significant performance gain at the cost of negligible increase of complexity. Furthermore, it is observed from simulation results that the proposed detector is not sensitive to the inaccuracy of channel estimation error statistics. Therefore, it can be a promising candidate to be applied in practical systems.

关 键 词：多入多出 最小均方误差 信道估计 软输出 

分 类 号：TN92[电子电信—通信与信息系统]